This invention relates to the replacement and regeneration of cardiac tissue and muscle.
This year over 300,000 Americans will die from congestive heart failure. The ability to augment weakened cardiac muscle would be a major advance in the treatment of cardiomyopathy and heart failure. Despite advances in the medical therapy of heart failure, the mortality due to this disorder remains high, where most patients die within one to five years after diagnosis.
A common heart ailment in the aging population is improper heart valve function, particularly the aortic valve. Mechanical replacement valves are widely used but require the patient to continually take blood thinners. Valves obtained from cadavers and xenographs (porcine) are also frequently used to replace a patient's own tissue. Valves are freeze-dried or chemically cross-linked using e.g., glutaraldehyde to stabilize the collagen fibrils and decrease antigenicity and proteolytic degradation. However, these valves remain acellular and often fail after several years due to mechanical strain or calcification. A replacement valve derived from biocompatible material that would allow ingrowth of the appropriate host cells and renewal of tissue over time would be preferred.
Mesenchymal stem cells (MSCs) are cells which are capable of differentiating into more than one type of mesenchymal cell lineage. Mesenchymal stem cells (MSCs) have been identified and cultured from avian and mammalian species including mouse, rat, rabbit, dog and human (See Caplan, 1991, Caplan et al. 1993 and U.S. Pat. No. 5,486,359). Isolation, purification and culture expansion of hMSCs is described in detail therein.